In machine milking systems it is important to milk the animal in an efficient manner, i.e. a fast and complete milking. That means that the milking of the animal should not take unnecessary long time and that all milk contained in the udder should be withdrawn and collected. This should also be performed while treating the animal and its teats gently so as not to inflict any pain or injuries.
In this respect the design of teat cups, comprising teat cup shells and teat cup liners, as well as for instance applied vacuum levels, are important factors for achieving the above mentioned goals.
Considerable efforts have been put in design of teat cups, especially teat cup liners of the teat cup to find solutions which treat the teats gently, and a number of different designs have been presented. However, it is also very important to achieve a fast milking for economic purposes and the strive for faster milking equipment, including teat cups and teat cup liners, is always present.
Most teat cups and teat cup liners are designed in a similar way. A teat cup liner comprises an orifice at the top end where a teat maybe introduced, and a vacuum is applied to the lower end of the teat cup liner for drawing milk from the teat and transporting the milk to a container. An alternating vacuum is supplied to the space between the teat cup and the teat cup liner to achieve a pulsating movement of the teat cup liner to thereby massage the teat.
The teat cup liner is often supplied with a space, or a collar, at the top end. That is, the teat cup liner has, at the top end, a part which has a greater inner diameter than the rest of the teat cup liner.
EP 277 396 disclose a method for cleaning a teat of a female animal and a teat cup for use with the above method. The teat cup comprises a conduit line connected to the space of a teat cup for supplying a washing agent.
WO98/28969 discloses a device and a method for milking animals. The disclosure is primarily concerned with that the teat cup may creep upwards during milking and suggests that this can be prevented by supply leakage air to the teat cup liner space in a controlled way to prevent the vacuum level therein to rise.
During milking in automated milking machines one common problem is that not all udder quarters finish milking simultaneously. This means that to draw all milk from the udder quarter finishing last, some udder quarters will be over-milked, resulting in bad treatment of these teats. None of the above mentioned disclosures mentions or provides any solution to this problem. The term udder quarter is not intended to be limited to animals having four teats in the present specification. For animals having less than four teats the term udder quarter means one of the teats.
Better utilization of milking equipment and designs improving utilization is always desirable.